The present invention relates to a battery pack and a charging control method that allow the battery pack to authenticate a charging device and prevent the charging device from charging the battery pack when the charging device is not an unauthorized charging device.
Since a secondary battery, for example a lithium ion battery, has features of small size, light weight, high energy density, high output, and so forth, it has been widely used for power supplies of application devices such as a digital camera, a cellular phone, a portable personal computer, and so forth. Such a lithium ion battery needs to be charged by a charging device manufactured by an authorized manufacturer to secure safe use of the battery and prevent the battery life from decreasing. For example, an unauthorized charging device may not satisfy necessary specifications. If the battery is charged by such an unauthorized charging device, the battery may be overcharged.
The following patent document 1 describes a related art reference of which a battery pack and an application device authenticate each other to prevent an authorized battery pack from being used.
[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-147408.
In the related art reference described in the patent document 1, a microcomputer disposed in a camcorder as an application device and a microcomputer disposed in a battery pack authenticate each other. According to the authenticated results, a power supply line of the camcorder is turned on or off. In the related art reference described in the patent document 1, the camcorder is prohibited from using a forged battery pack that unlikely satisfies the specifications of the camcorder. In other words, the related art reference described in the patent document 1 does not intend to prevent an unauthorized charging device from charging an authorized battery pack.